Systems and methods for lighting fixtures

ABSTRACT

Examples of the present disclosure are related to systems and methods for lighting fixtures. More particularly, embodiments disclose lighting fixtures utilizing metal core PCB (MCPCB) for optical controls.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims a benefit of priority under 35 U.S.C. § 119 toProvisional Application No. 62/516,412 filed on Jun. 7, 2017, and is acontinuation of U.S. Ser. No. 15/829,197 filed on Dec. 1, 2017, whichare fully incorporated herein by reference in their entirety.

BACKGROUND INFORMATION Field of the Disclosure

Examples of the present disclosure are related to systems and methodsfor lighting fixtures. More particularly, embodiments disclose lightingfixtures utilizing multiple bends in a light fixture comprised ofmetal-core PCB (MCPCB) for increasing efficiency in optical performance.

Background

Controlled environment agriculture, especially vertical farming isbecoming more prevalent in the US and around the world. Vertical farmingrelies on light fixtures to illuminate a plant canopy. The lightfixtures uniformly distribute radiant flux over the plant canopy, whileremoving heat from light sources (typically LEDs). The light fixtures'efficacy and cost directly impacts the operational expenses associatedwith vertical farming. As fixture height directly influences a number ofvertical layers within a growth volume, it is important to minimize aform factor or vertical height of the fixture

Operating higher-powered lights in a vertical growth is more costly thanutilizing free sunlight in greenhouses or field-grown. To overcome thesecosts, vertical farming must have increased yields, shorter growthcycles, more consistent product, less water usage, reduce farm to platetimeframe, higher nutrient content, and other tangible advantages.

Accordingly, needs exist for more effective and efficient systems andmethods for light fixtures with LEDS integrated directly into MCPCB,wherein the MCPCB includes one or more bends for optical controls toincrease radiant flux on the plant and thus yield.

SUMMARY

Embodiments disclosed herein describe systems and methods for a lightfixture that utilizes MCPCB and positioning of LEDs for opticalcontrols. In embodiments, a substrate, such as a MCPCB sheet, may bedirectly populated with electronic components, such as LEDS, connectors,fuses, etc. The MCPCB sheet may then be coated for protection. The MCPCBsheet may then be cut into a single panel. Next, the single panel MCPCBis bent at least one time, wherein the length and angle of the bends maybe utilized for optically controlling a distribution pattern andradiance of light emitted from the light sources on an area of interest.The bent MCPCB panel can then be assembled into a light fixture.Embedded light sources and corresponding electronics directly with aMCPCB may allow for lower material costs, lower labor costs, andsuperior thermal performance. Specifically, costs may be reduced by notrequiring heatsink, adhesives, or other thermal interface materials.Additionally, costs may be reduced by not requiring fasteners, clips,etc. to couple the heatsink to the MCPCB.

Labor costs may also be reduced by removing the steps of adhesivedispensing or tape dispensing, MCPCB placement process, and time to cureor set the adhesive or tape.

Embodiments may include a MCPCB panel, at least one row of LEDs, and atleast one bend in the MCPCB panel.

The MCPCB panel may be formed of copper, 3003 AL, 5052 AL, and/or otherdesired metals. In implementations, the preferred MCPCB may not beformed of a metal with a very low emissivity. To increase the emissivityof the MCPCB panel, the panel may be anodized, may have a solder maskthat yields higher emissivity than anodized aluminum, and/or have apainted surface that yields higher emissivity than anodized aluminum.

The row(s) of LEDs may be positioned from a first end to a second end ofthe MCPCB panel, which may extend along the longitudinal axis of theMCPCB panel. The rows of LEDs may be symmetrically or asymmetricallyspaced from the central axis of the MCPCB panel. Symmetricalimplementations of the positioning of the LEDs may allow for even andsymmetrical optical controls, and asymmetrical LED placement withregards to the longitudinal axis of the MCPCB may allow for asymmetricallight patterns.

The bends in the MCPCB may extend from the first end to the second endof the MCPCB panel. The bends may be configured to add rigidity and/ormechanical strength, add form for aesthesis, and allow for opticalcontrols, such as being a diffuse/specular reflector. The bends in theMCPCB may be downward and outwardly angled bends, which are configuredto extend away from the central axis of the MCPCB panel towards a lowersurface. The angle and length of each of the bends may be configured tocontrols a light pattern positioned on an area of interest below thefixture.

Furthermore, in systems with multiple bends on each side of the lightsources, the bends that encompasses the greatest angular subtense mayaffect the optical controls of the light fixture more than bends withsmaller angular subtense.

These, and other, aspects of the invention will be better appreciatedand understood when considered in conjunction with the followingdescription and the accompanying drawings. The following description,while indicating various embodiments of the invention and numerousspecific details thereof, is given by way of illustration and not oflimitation. Many substitutions, modifications, additions orrearrangements may be made within the scope of the invention, and theinvention includes all such substitutions, modifications, additions orrearrangements.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting and non-exhaustive embodiments of the present invention aredescribed with reference to the following figures, wherein likereference numerals refer to like parts throughout the various viewsunless otherwise specified.

FIG. 1 depicts a light fixture system configured for optical controls,according to an embodiment.

FIG. 2 depicts a system to optically control light patterns emitted fromlight sources, according to an embodiment.

FIG. 3 depicts a system optically control light patterns emitted fromlight sources, according to an embodiment.

FIG. 4-5 depict a symmetrical light distribution pattern created by asystem on an area of interest, according to an embodiment.

FIGS. 6-8 depict a system to optically control light patterns emittedfrom light sources, according to an embodiment.

FIGS. 9-11 depict a system to optically control light patterns emittedfrom light sources, according to an embodiment.

FIGS. 12-13 depict a system to optically control light patterns emittedfrom light sources, according to an embodiment.

Corresponding reference characters indicate corresponding componentsthroughout the several views of the drawings. Skilled artisans willappreciate that elements in the figures are illustrated for simplicityand clarity and have not necessarily been drawn to scale. For example,the dimensions of some of the elements in the figures may be exaggeratedrelative to other elements to help improve understanding of variousembodiments of the present disclosure. Also, common but well-understoodelements that are useful or necessary in a commercially feasibleembodiment are often not depicted in order to facilitate a lessobstructed view of these various embodiments of the present disclosure.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth inorder to provide a thorough understanding of the present embodiments. Itwill be apparent, however, to one having ordinary skill in the art thatthe specific detail need not be employed to practice the presentembodiments. In other instances, well-known materials or methods havenot been described in detail in order to avoid obscuring the presentembodiments.

FIG. 1 depicts a light fixture system 100 configured for opticalcontrols, according to an embodiment. System 100 may be configured toutilize bends in a MCPCB lighting fixture for optical controls. System100 may include MCPCB 110, light sources 120, and bends 130. Utilizingbends 130, MCPCB 110 may optically control the light output from lightsources 120.

MCPCB 110 may be formed of any metal, including: silver, tin, gold,copper, 3003 AL, 5052 AL, and/or other desired metals. In specificimplementations, MCPCB 110 may be formed of a metal or substrate with avery low emissivity. However such a system would be much larger than asystem with a high emissivity platform. To increase the emissivity ofthe MCPCB 110, MCPCB 110 may be anodized, may have a solder mask thatyields higher emissivity than anodized aluminum, and/or have a paintedsurface that yields higher emissivity than anodized aluminum. MCPCB 110may be positioned in a panel having a longer longitudinal axis than alateral axis. MCPCB 110 may also include specular reflectors, diffusereflectors, and engineered diffusers for beam control. For example,MCPCB 110 may utilize bare tin for specularly reflective surfaces or asecondary reflective surface such as adhering reflective tape,reflectors, Alanod, or other engineered diffusers to the MCPCB.

Light sources 120 may be light emitting diodes (LEDs) or any otherdevice that is configured to emit light. Light sources 120 may bedirectly embedded or positioned on MCPCB 110, such that additionaloperations to affix tape or thermal adhesives to MCPCB 110, a heat sink,or both are not required. Light sources 120 may be positioned from afirst end of MCPCB 110 to a second end of MCPCB 110. Light sources 120may be configured to generate heat in response to creating and emittinglight. Light sources 120 may be arranged on MCPCB 110 in a plurality ofrows, or in any predetermined layout to generate a desired light patternon an area of interest positioned below system 100. In embodiments, therows of light sources 120 may be symmetrically placed around and/orthrough the central axis of MCPCB 110 to emit an even light pattern andto generate even amounts of heat. However, in other embodiments, thelights sources 120 may be asymmetrically positioned to generate adesired light pattern on a region of interest. In embodiments,reflectors and diffusers may be positioned around light sources 120after the light sources 130 are positioned on MCPCB 110.

Bends 130 may be positioned from the first end to the second end ofMCPCB 110. Bends 130 may be configured to add rigidity and/or mechanicalstrength to system 100, add form for aesthetics, operate as a heat sinkto guide the flow of air, and allow for optical controls. Bends 130 maybe positioned at an angle that is perpendicular to MCPCB 110 orpositioned at an angle that is downward and away from a central axis ofMCPCB 110. By angling bends 130 away from the central axis and towards alower surface, thermal performance of system 100 may be increased. Morespecifically, air that is heated by light sources 120 (and otherelectronics) under MCPCB 110, may travel towards the lower distal endsof bends 130, around the distal ends of bends 130, and upwards towardsthe central axis of system 100 positioned above MCPCB 110. Inembodiments, reflectors may be positioned on bends 130.

The heights of bends 130 may be based on the length of MCPCB 110,wherein the heights of bends may be the vertical distance from thedistal ends of bends 130 to the upper surface of MCPCB 110. Inembodiments where the length of MCPCB 110 is longer, the height of bends130 may be taller. In embodiments where the length of MCPCB 110 isshorter, the height of bends 130 may be shorter.

In embodiments, based on the geometric properties of bends 130, bends130 may be utilized for optical control of the light emitted from lightsources 120. Specifically, the bends 130 may be used as adiffuse/speculator reflector for the light emitted from light sources120. This may enable system 100 to alter, change, and/or create adesirable light pattern on an area of interest below system 100.

In embodiments, the materials, angles, lengths, heights, and/or othergeometrical properties of bends 130 (or the panels created by bends) maybe symmetrical across the central axis such that MCPCB 110 isisothermal. Yet, in other implementations, the materials, angles,lengths, heights, and/or other geometric properties of bends 130 (or thepanels created by bends may be asymmetric. For example, differentsystems may be created with different geometric layouts. For example,system 100 may only include one row of light sources extending along thecentral axis of the MCPCB. Additionally, the length of the bends inother systems may be shorter than that of system 100, and the spacing ofthe lights in other systems may be different than that of system 100.The geometric properties of the different systems may be utilized foroptical controls to emit different desired light patterns on differentareas of interest.

FIG. 2 depicts a system 200 to optically control light patterns emittedfrom light sources 120, according to an embodiment. Elements depicted inFIG. 2 may be described above, and for the sake of brevity an additionaldescription of these elements is omitted.

As depicted in system 200, MCPCB 110 may include multiple bends thatform individual panels. Specifically, the system 100 depicted in FIG. 2includes four bends with two bends 212, 222 positioned on both sides ofa center panel 205 where light sources 120 are positioned. However, inother embodiments, system 100 may include any number of bends, which maybe the same or different number on the different sides of center panel205

First bend 212 may be positioned between center panel 205 and firstpanel 210, and second bend 222 may be positioned between second panel220 and first panel 210. In embodiments, first bend 212 may be the sameor different angle as second bend 222, and first panel 210 may be thesame or different length as second panel 220.

In embodiments, the subtended angle from the center of the board tofirst bend 212 to a distal end of the outermost panel (second panel 220)may determine a level the optical control of system 200. The level ofoptical control may determine a light intensity, uniformity, spread,pattern etc. on an area of interest positioned below system 100.Increasing the subtended angle increases the level of optical control oflight sources 120, whereas decreasing the subtended angle decreases thelevel of optical control of light sources 120. LED sources (as with mostsources) are Lambertian emitters. In the MCPCB system, the sidewallreflectors modify the radiant intensity distribution from Lambertian.The maximum center beam radiant intensity may be calculated from thebrightness equation:

$\frac{\varnothing_{1}}{n_{1}A_{1}\Omega_{1}} = \frac{\varnothing_{2}}{n_{2}A_{2}\Omega_{2}}$

Where φ is the flux, n is the index of refraction, A is the area and Ωis the solid angle of the system. Assuming the starting index ofrefraction of the source and the region of interest are the same (n=1for air), the equation reduces to:

$\frac{\varnothing_{1}}{A_{1}\Omega_{1}} = \frac{\varnothing_{2}}{A_{2}\Omega_{2}}$

Radiant Intensity is Flux divided by solid angle.

${\frac{\varnothing_{1}}{A_{1}\Omega_{1}}A_{2}} = {\frac{\varnothing_{2}}{\Omega_{2}} = {{radiant}\mspace{14mu} {intensity}}}$

From the equation, Radiant intensity is proportional to the area of theoptic. In this case the optic is the MCPCB reflector, and the area isthe opening at the distal end of the bends. To increase radiantintensity, the exit aperture size of the optic needs to beproportionally increased.

Furthermore, a length of each of the panels 210, 220 may determine theeffect of each of the panels 210, 220 on the overall light distributionof system 200. By increasing a length of a panel 210, 220, then thatpanel will have a greater effect of the overall light distribution ofsystem 200. Conversely, decreasing the length of a panel 210, 200, maydecrease the effect of the panel of the light distribution of system200. Similarly, a specific angle of the bend 212, 222 may affect thelight distribution of system 200, wherein increasing the angle of a bend212, 222 increases the effect of the overall light distribution.

FIG. 3 depicts a system 300 to optically control light patterns emittedfrom light sources 302, 304, 306, 308, according to an embodiment.Elements depicted in FIG. 3 may be described above, and for the sake ofbrevity an additional description of these elements is omitted.

Specifically, FIG. 3 depicts an eight bend system for tighter opticalcontrols, wherein four bends 312, 314, 316, 318 are positioned on eachside of a the light sources 302, 304, 306, 308. The four bends 312, 314,316, 318 may be utilized to create four panels 310, 320, 330, 340 havingreflective surfaces. As depicted in FIG. 4, the four panels 310, 320,330, 340 may have equal lengths. Furthermore, the light sources 302,304, 306, 308 may be positioned equidistance from the first panels 312positioned on both sides of the light sources 302, 304, 306, 308.

FIG. 4-5 depict a symmetrical light distribution pattern 410 created bysystem 300 on an area of interest 420 positioned below system 300.Furthermore, the light distribution pattern 410 created by system 300may have a substantially uniform radiant intensity.

FIGS. 6-8 depict a system 600 to optically control light patternsemitted from light sources, according to an embodiment. Elementsdepicted in FIGS. 6-8 may be described above, and for the sake ofbrevity an additional description of these elements is omitted.

In system 600, the light sources 602, 604, 606, 608 may be positionedclosed to one of the first bends 602 on either the right or the leftsides of light sources 602, 604, 606, 608. This may be utilized tocreate an asymmetrical light distribution pattern 610 with anasymmetrical radiant intensity 620 on the area of interest. In system600, the properties of the bends and the panels 610, 620, 630, 640 onthe left and right sides of system 600 may be the same. Yet, because ofthe asymmetrical positioning of light sources 602, 604, 606, 608 on acenter panel, the light distribution pattern 610 and radiant intensity620 may be asymmetrical. However, in other embodiments, to create aasymmetrical light distribution pattern 610 or radiant intensity 620,the panel lengths, a number of panels, and bend angles on the left andright side of light sources 602, 604, 606, 608 may be different.

FIGS. 9-11 depict a system 900 to optically control light patternsemitted from light sources, according to an embodiment. Elementsdepicted in FIGS. 9-11 may be described above, and for the sake ofbrevity an additional description of these elements is omitted.

As depicted in FIGS. 9-11, system 900 may have two bends forming twopanels 910, 920. The light sources associated with system 900 may bepositioned equal distance from a first bend associated with panels 910on each side of the light sources, wherein the panels 910, 920 andangles of the bends on both sides of the light systems may be the same.This layout may be utilized to create a symmetrical light distributionpattern on an area of interest positioned below system 900, with asubstantially uniform radiant intensity.

FIGS. 12-13 depict a system 1200 to optically control light patternsemitted from light sources, according to an embodiment. Elementsdepicted in FIGS. 12-13 may be described above, and for the sake ofbrevity an additional description of these elements is omitted.

As depicted in system 1200, system 1200 may include eight bends 1202,1204, 1206, 1208, with four bends positioned on both sides of lightsources 1205. This may result in eight panels 1210, 1220, 1230, 1240within system 1200. Due to the positioning of light sources 1205 beingequal distance to first bends 1202 and the characteristics of angles ofbends 1202, 1204, 1206, 1208 and lengths of panels 1210, 1220, 1230,1240 on both sides of light sources being equal, the light distributionpattern and radiant intensity on an area of interest below system 1200may be symmetrical.

Although the present technology has been described in detail for thepurpose of illustration based on what is currently considered to be themost practical and preferred implementations, it is to be understoodthat such detail is solely for that purpose and that the technology isnot limited to the disclosed implementations, but, on the contrary, isintended to cover modifications and equivalent arrangements that arewithin the spirit and scope of the appended claims. For example, it isto be understood that the present technology contemplates that, to theextent possible, one or more features of any implementation can becombined with one or more features of any other implementation.

Reference throughout this specification to “one embodiment”, “anembodiment”, “one example” or “an example” means that a particularfeature, structure or characteristic described in connection with theembodiment or example is included in at least one embodiment of thepresent invention. Thus, appearances of the phrases “in one embodiment”,“in an embodiment”, “one example” or “an example” in various placesthroughout this specification are not necessarily all referring to thesame embodiment or example. Furthermore, the particular features,structures or characteristics may be combined in any suitablecombinations and/or sub-combinations in one or more embodiments orexamples. In addition, it is appreciated that the figures providedherewith are for explanation purposes to persons ordinarily skilled inthe art and that the drawings are not necessarily drawn to scale.

The flowcharts and block diagrams in the flow diagrams illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowcharts or block diagrams may represent a module, segment, or portionof code, which comprises one or more executable instructions forimplementing the specified logical function(s). It will also be notedthat each block of the block diagrams and/or flowchart illustrations,and combinations of blocks in the block diagrams and/or flowchartillustrations, may be implemented by special purpose hardware-basedsystems that perform the specified functions or acts, or combinations ofspecial purpose hardware and computer instructions.

1. A system for optically controlling a light pattern, the systemcomprising: a substrate; a first bend extending along a longitudinalaxis of a first side of the substrate; a second bend extending along aside of the first bend.
 2. The system of claim 1, wherein a first angleassociated with the first bend is different than a second angleassociated with the second bend.
 3. The system of claim 1, wherein thefirst bend extends away from a central axis of the substrate.
 4. Thesystem of claim 1, further comprising: a third bend extending along alongitudinal axis of a second side of the substrate; a fourth bendextending along a side of the third bend.
 5. The system of claim 1,wherein at least one light source is positioned between the first sideof the substrate and a second side of the substrate.
 6. The system ofclaim 1, further comprising: a first panel positioned between the firstbend and the second bend; a second panel positioned on the second bend.7. The system of claim 6, wherein a subtended angle from a central axisof the substrate to a distal end of the second panel determines a levelof optical control.
 8. The system of claim 6, wherein the level ofoptical control is associated with at least one of light intensity,uniformity, and spread of light emitted on an area of interestpositioned below the substrate.
 9. The system of claim 6, wherein afirst width of the first panel is different than a second width of thesecond panel.
 10. The system of claim 1, wherein the substrate is formedof metal core printed circuit board.
 11. A method for opticallycontrolling a light pattern comprising: forming a first bend along alongitudinal axis of a first side of a substrate; forming a second bendalong a side of the first bend.
 12. The method of claim 11, wherein afirst angle associated with the first bend is different than a secondangle associated with the second bend.
 13. The method of claim 11,wherein the first bend extends away from a central axis of thesubstrate.
 14. The method of claim 11, further comprising: forming athird bend along a longitudinal axis of a second side of the substrate;forming a fourth bend along a side of the third bend.
 15. The method ofclaim 11, further comprising: positioning at least one light sourcebetween the first side of the substrate and a second side of thesubstrate.
 16. The method of claim 11, wherein a first panel is formedbetween the first bend and the second bend, and a second panel ispositioned on the second bend.
 17. The method of claim 16, furthercomprising; determining a level of optical control based on a subtendedangle, the subtended angle being from a central axis of the substrate toa distal end of the second panel.
 18. The method of claim 16, whereinthe level of optical control is associated with at least one of lightintensity, uniformity, and spread of light emitted on an area ofinterest positioned below the substrate.
 19. The method of claim 16,wherein a first width of the first panel is different than a secondwidth of the second panel.
 20. The method of claim 11, wherein thesubstrate is formed of metal core printed circuit board.